Posted
by
Soulskill
on Tuesday January 15, 2013 @04:50PM
from the microbial-hide-and-seek-continues dept.

The Bad Astronomer writes "News is going around the web that a scientist in the UK has found life (in the form of microscopic diatoms) in a meteorite, and has even published a paper about it. However, there are a lot of reasons to strongly doubt the claim. While the diatoms appear to be real, they are certainly from Earth. The meteorite itself, on the other hand, does not appear to be real. Many of the basic scientific steps and claims made in the paper are very shaky. Also, the scientist making the claim, N. C. Wickramasinghe, has made many fringe claims like this in the past with little or no evidence (such as the flu and SARS being viruses from space). To top it off, the website that published the paper, the Journal of Cosmology, has an interesting history of publishing fringe claims unsupported by strong evidence. All in all, this claim of life in a space rock is at best highly doubtful, and in reality almost certainly not true."

No question those are diatoms. More specifically, most are pennate ones (Order Pennales), although there is a picture of a filamentous Centrales diatom in the appendix. But why the hell they would base the in-situ interpretation on an elemental analysis rather than identifying the species present and seeing if "coincidentally" they happened to be the same species as ones found in the local freshwater lakes and streams is a bit of a mystery.

The paper isn't exactly rigorous. For one thing they say diatoms date back to the Cretaceous/Tertiary boundary. No, they date back to the Jurassic Period -- considerably earlier. Furthermore they attribute them to marine environments. No, they are found in marine and freshwater environments. They are also commonly observed as thin crusts on rocks in moist environments (i.e. it doesn't have to be standing or flowing water, just wet). "Hydrated silicon dioxide polymer"? Well, I suppose. But most people who actually work on them call it opaline silica (which is indeed the same thing, it's just weird terminology to use). I don't know what they mean by "fossilized". Diatoms don't have to "fossilize" in the sense of any mineralization or alteration being necessary. They're already opaline silica. All that has to happen for them to preserve for the long term is not dissolve away, and silica is already pretty low solubility, essentially glass. Diatoms are generally quite durable structures.

Not much of a peer review, that's for sure. It's pretty obvious this is almost certainly modern contamination. They don't provide a speck of useful information showing that it's not. A bunch of EDX chemical analyses merely confirm the composition. So what? It would have been a lot more useful to make a petrographic thin section and figure out the relationship of the diatoms to the mineral grains in the rock.

The racist attack in the GP post certainly deserved some scorn. As for the people themselves, I don't know much about Wikramasinghe, but I know that Hoyle was brilliant and accomplished and also a bit of an over-opinionated nut. His absurd position on the authenticity of Archaeopteryx attests to that. Wikramasinghe was apparently his student and shared many of his ideas, including the ones about Archaeopteryx. It seems to me that they formed some pretty solid theories about the cosmological origins of various molecules fundamental to known life, along with some less sound, but still compelling theories about the origins of life itself, and then some over the top wild speculation and wishful thinking.